The listing is for BOTH gears involved in the BMW transfer case used in X3, X5, X6 etc.
The transfer case actuator is a common and frequent cause of failure due to worn out gears
The replacement of the entire motor/case is costly. We offer the failing/wearing gears as an individual part as an inexpensive solution to this common problem.
Often it is advantageous to replace BOTH gears 'while in there'.
We offer each gear also individually (and have over 6,000 installed).